This invention relates to an air intake arrangement for an outboard motor, and more particularly to an improved protective cowling and air inlet arrangement for the power head of an outboard motor.
It is well known with outboard motors that the powering internal combustion engine is normally enclosed within a protective cowling so as to provide protection and a better appearance, as well as a noise silencing function, for the outboard motor. The protective cowling defines a cavity in which the internal combustion engine is contained.
It is also well known that the engine must be supplied with copious amounts of air for the engine induction system. Conventionally, the protective cowling includes an air inlet positioned in the upper rear portion thereof. This air inlet generally has an upwardly and rearwardly facing opening, and may have sidewardly facing openings as well, to permit air to flow into the cavity of the protective cowling for supply to the engine induction system. See for example U.S. Pat. No. 4,571,193 to Takada et al. Typically a further cowling member is provided that extends across the rearwardly facing air inlet opening so as to prevent foreign objects from falling into this inlet. The further cowling member also defines the overall cowling arrangement along the region of the rearwardly facing air inlet opening.
Air inlets with rearwardly facing openings are normally incorporated so that under normal operating conditions water will not enter into the interior of the cowling and the engine induction system. One such arrangement includes a midway chamber disposed between the air intake port of the cowling and the induction system of the engine. In this arrangement, any water which might enter the cowling along with the air is generally separated from the air within the midway chamber. Under certain conditions, however, such an arrangement can permit water to enter into the interior of the protective cowling and damage the engine. Such damage can take the form, for example, of engine corrosion, especially when the vessel is operating in a body of salt water. Further, the electrical parts of the outboard motor may be damaged, or water may enter the induction system of the engine and impair engine performance. Such an air inlet can be especially susceptible to the entry of water when the speed of the marine vessel is quickly reduced during operation so that a wave strikes the rear of the marine vessel and outboard motor.
It is, therefore, a principle object of this invention to provide an improved cowling and air inlet arrangement for the powerhead of an outboard motor which will prevent water from splashing upon the outer surface of the engine, thereby preventing corrosion of the engine's outer surface.